THE DISRUPTIVE POTENTIAL OF SUBSONIC AIR-LAUNCH
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Transcript of THE DISRUPTIVE POTENTIAL OF SUBSONIC AIR-LAUNCH
© Telespazio VEGA Deutschland 20/11/2014
Telespazio VEGA Deutschland
THE DISRUPTIVE POTENTIAL OF
SUBSONIC AIR-LAUNCH
12th Reinventing Space Conference
Royal Society, London
18-21 November 2014
David J. Salt - Senior Consultant
© Telespazio VEGA Deutschland 20/11/2014 2
QUESTION: DO WE NEED
BIG LAUNCHERS
TO ENABLE
BIG SPACE ACTIVITIES?
The Disruptive Potential of Subsonic Air-Launch
© Telespazio VEGA Deutschland 20/11/2014 3
PRESENTATION OVERVIEW
The Limits to Growth
The Current Space Paradigm & Constraints on Commercial Space
What’s the Problem?... The Space Access Dilemma & Potential for ‘Disruption’
The Case for Subsonic Air-Launch
Benefits of Subsonic Air-Launch & Operational Concept
Benefits of Air Collection & Boost to RLV Performance
Operating Beyond the Limits
LEO Operations & Beyond
Commercial GEO Operations
Conclusions
The Disruptive Potential of Subsonic Air-Launch
© Telespazio VEGA Deutschland 20/11/2014 4
The Limits to Growth
THE CURRENT SPACE PARADIGM
The current ‘space paradigm’ is stagnating!
space activities are still dominated by government programmes supported by
‘commercial’ contractors
all programmes take longer and cost more than planned
future programmes face cut-backs and/or cancellation due to major constraints on
government discretionary spending
The Disruptive Potential of Subsonic Air-Launch
A POTENTIAL FOR GROWTH?
Perspective: The 2012 global space revenue
was $304 billion, which is less than the annual
revenue of one large commercial company
(e.g. Wal-Mart)
World airline revenues in 2012 were $700 billion
Lufthansa’s revenue in 2012 was $39 billion
Question: Without another major government
initiative like Apollo, how can we encourage
and/or create new space markets?
© Telespazio VEGA Deutschland 20/11/2014 5
The Limits to Growth
WHAT’S THE PROBLEM?
We have much better supporting technologies than we had 50 years ago,
when Apollo began
manufacturing processes and computer hardware/software have made huge
advances and become cheaper!
Nevertheless, commercial space activities are limited to working with
‘photons’ rather than ‘atoms’ because of the space launch dilemma
The Disruptive Potential of Subsonic Air-Launch
THE SPACE ACCESS DILEMMA
Space access is expensive… the price to get into low Earth orbit is on the
order of $10,000/kg because current launcher vehicles are extremely
expensive to operate
Expendables (e.g. Ariane 5) throw away expensive hardware
Repairables (i.e. Shuttle) take too much time/effort to turn-around
Fully reusable launchers with airline-like operations could lower the cost of
space access by at least an order of magnitude (less than $1,000/kg) but…
the estimated cost to develop such vehicles is $10-20 billion
current markets are insufficient to reach flight rates that would justify such a cost
because… space access is expensive!
© Telespazio VEGA Deutschland 20/11/2014 6
The Limits to Growth
THE POTENTIAL FOR ‘DISRUPTION’
The Disruptive Potential of Subsonic Air-Launch
The current paradigm is very unlikely to overcome these limits to growth,
especially if current launch markets remain ‘inelastic’
lower prices stimulate only limited market growth and, worse still, result in a
significant decrease in total yearly revenue!
One way to overcome this is to radical drop launch prices below $1000/kg,
which can only be achieved via a mature RLV
Another is to stimulate new markets with better elasticity and reduced
performance demands (e.g. sub-orbital flights) that can be serviced by
smaller/cheaper vehicles
Bridging the performance gap between current and new markets will be
critical to realizing this ‘disruptive’ path
This work tries to show how a small subsonic air-launched RLV with
operational flexibility and growth potential could resolve this dilemma
© Telespazio VEGA Deutschland 20/11/2014 7
The Case for Subsonic Air-Launch
CAVEAT & RATIONALES FOR SUBSONIC AIR-LAUNCH
Subsonic air-launch should be regarded as an enabling capability for a
launch system, not a launch solution in and of itself
the majority of the technology/cost challenge still reside within the rocket
that performs the bulk of the work needed to place any payload into orbit
best thought of as a mobile, high altitude launch facility
It provides performance and operational advantages BUT it does increase
the costs/complexity of the overall launch system
Performance advantages translate into a relaxation of design constraints,
which tend to be better exploited by an RLV than an ELV
relaxation of RLV design constraints make their challenges far more tractable,
realistic and affordable
for ELVs (e.g. Pegasus), these advantages tent to be outweighed by the
drawback unless the prime need is for rapid/flexible launch
The Disruptive Potential of Subsonic Air-Launch
© Telespazio VEGA Deutschland 20/11/2014 8
The Case for Subsonic Air-Launch
THE BENEFITS OF SUBSONIC AIR-LAUNCH
Performance benefits
rocket operations above the dense atmosphere
reduce significantly both drag and gravity losses
enables significant increase in engine specific
impulse (Isp) by using a larger expansion ratio
nozzle that would be over-expanded at lower
altitudes so cause destructive instabilities
The Disruptive Potential of Subsonic Air-Launch
Operational benefits
enables operation out of existing airports with reduced launch range constraints
increases launch window flexibility and orbital rendezvous opportunities
up-range launch enables 1st stage to land back at base, minimising ferry flights
Cost & Evolutionary benefits
existing aircraft can be procured/modified at relatively low cost
aircraft can be modified incrementally to increase performance (e.g. better
thrust/weight/performance engines and/or introduction of ACES equipment)
© Telespazio VEGA Deutschland 20/11/2014 9
The Case for Subsonic Air-Launch
SUBSONIC AIR-LAUNCH OPERATIONS & WINDOWS
The Disruptive Potential of Subsonic Air-Launch
Cruise to launch point has major benefits
increases daily launch window opportunities
reduces ‘dog-leg’ for LEO rendezvous
enables atmospheric LOx ‘harvesting’
© Telespazio VEGA Deutschland 20/11/2014 10
The Case for Subsonic Air-Launch
BENEFITS OF AIR COLLECTION & ENRICHMENT
Use of existing aircraft limits RLV mass and therefore
payload performance to LEO
The gross mass of any launch vehicle using liquid
oxygen (LOx) will be dominated by the LOx mass
The Disruptive Potential of Subsonic Air-Launch
Candidate Aircraft External
Mass (Mg)
An-225 200
A380-800F 120
747-100 SCA -911 109
747-400F 140
Dual-fuselage C-5 350
Stratolaunch Carrier 120
oxidiser/fuel rations of 5.2 for liquid hydrogen (LH2) and 2.3 for kerosene (RP-1)
mean that LOx is more than half the RLV gross mass at take-off!
Any method that enables the LOx to be loaded after take-off should offer a
number of significant advantages
increased RLV mass and so payload performance to LEO for any given aircraft
improved safety during ground operations and take-off due to elimination of LOx
Two approaches appear possible
transfer the LOx in-flight from a ‘tanker’ aircraft
utilise the cruise phase to harvest the LOx from the atmosphere
Harvesting LOx via an Air Collection and Enrichment System (ACES) offers
the safer and operational less complex option
© Telespazio VEGA Deutschland 20/11/2014 11
The Case for Subsonic Air-Launch
ACES CONCEPTUAL DESIGN & OPERATION
ACES generates LOx by ingested air and separating out nitrogen and other
component via heat exchangers and a rotational fractional distillation unit
The heat exchangers use LH2 to super-cool incoming air tapped off the
aircraft’s main engines or drawn in by a dedicated compressor
The resulting LOx is then pumped from the ACES system on the carrier
aircraft into the empty LOx tanks of the launch vehicle during flight
The Disruptive Potential of Subsonic Air-Launch
© Telespazio VEGA Deutschland 20/11/2014 12
The Case for Subsonic Air-Launch
ACES BOOST TO RLV PERFORMANCE
Parametric models of two RLV concepts were developed to investigate the
impact of ACES on LEO payload performance
a two-stage design using LOx/RP on the 1st stage and LOx/LH2 on the 2nd stage
a two-stage liquid design using LOx/LH2 on both stages
RLV mass/performance data was taken from NASA/DARPA & ESA studies
Conservative ACES characteristics were taken from US & European studies
The Disruptive Potential of Subsonic Air-Launch
© Telespazio VEGA Deutschland 20/11/2014 13
Operating Beyond the Limits
LEO OPERATIONS & BEYOND… “HALFWAY TO ANYWHERE”
Most space station crew
and logistics transport
requirements could be
supported by a subsonic
air-launched RLV
Mass of many GEO and
lunar transport elements
could also be supported
by this same RLV
The vast majority (~80%)
of mass launched to LEO
will be propellant, which
is infinitely divisible!
The Disruptive Potential of Subsonic Air-Launch
ISS Servicing Vehicles LEO Mass (Mg)
Soyuz (Government – Russian) 7200
Progress (Government – Russian) 7200
ATV (Government – European) 20200
HTV (Government – Japanese) 19000
Dragon (Commercial – SpaceX) 6000
Cygnus (Commercial – OSC) 4500
© Telespazio VEGA Deutschland 20/11/2014 14
Operating Beyond the Limits
COMMERCIAL GEO OPERATIONS
A suborbital air-launched RLV with
4000kg LEO payload performance
can also launch GEO comsats
40% of GEO comsat launch mass is
propellant to go from GTO to GEO
Operational scenario would involve
launch/assembly of a kick stage to
perform LEO to GEO transfer
number of launches depends on
satellite’s Beginning of Life (BoL)
mass
final launch delivers/mates satellite
with kick-stage
Preliminary business case analysis
suggests an RLV with development
costs below $1billion could be a
commercially viable proposition!
The Disruptive Potential of Subsonic Air-Launch
© Telespazio VEGA Deutschland 20/11/2014 15
Conclusions
CONCLUSIONS
Space activities have so far failed to achieve the great expectations set out
at the dawn of the space age, over half a century ago
Access to LEO (i.e. launch vehicles) is one of the main constraining factors
for in-space developments and operations
A subsonic air-launched RLV could improve access to LEO significantly, in
terms of safety, availability and cost
Such an RLV could support new space infrastructures that would increase
future in-space operations for both exploration and resource exploitation
These developments could be driven by commercial investments, though
there is much scope for governments to foster them in a synergistic manner
Although more detailed analyses are needed in order to confirm these
results, they do tend to suggest that…
We don’t need big launchers to enable big space activities!
The Disruptive Potential of Subsonic Air-Launch
© Telespazio VEGA Deutschland 20/11/2014 16
THANKS FOR YOUR ATTENTION…
… ANY QUESTIONS?
The Disruptive Potential of Subsonic Air-Launch
© Telespazio VEGA Deutschland 20/11/2014 17
SUPPLEMENTARY SLIDES
The Disruptive Potential of Subsonic Air-Launch
© Telespazio VEGA Deutschland 20/11/2014 18
The Case for Subsonic Air-Launch
The Disruptive Potential of Subsonic Air-Launch
ACES CYCLE DESIGN & EXPERIMENTAL TEST HARDWARE
© Telespazio VEGA Deutschland 20/11/2014 19
Supplementary Slides
ACES SCHEMATIC
The Disruptive Potential of Subsonic Air-Launch
© Telespazio VEGA Deutschland 20/11/2014 20
Supplementary Slides
NASA/DARPA DESIGN CONCEPTS (PD-2 & PD-3)
The Disruptive Potential of Subsonic Air-Launch
© Telespazio VEGA Deutschland 20/11/2014 21
Supplementary Slides
EVOLUTIONARY STEPS FOR A ‘BIMESE’ RLV
The Disruptive Potential of Subsonic Air-Launch
© Telespazio VEGA Deutschland 20/11/2014 22
Supplementary Slides
RLV SCALING RELATIONSHIPS
x
The Disruptive Potential of Subsonic Air-Launch
© Telespazio VEGA Deutschland 20/11/2014 23
Supplementary Slides
SELECTION OF EXTERNAL CARRIAGE AIR-LAUNCH CONCEPTS
(EXCLUDES TOWED OR INTERNAL CARRIAGE)
The Disruptive Potential of Subsonic Air-Launch
Config. Concept Name Designer/Year Air-launch Vehicle Propellant Reusable Payload
Cap
tiv
e o
n T
op
Boeing AirLaunch USA/1999 747 Solid No 3.4t
Interim HOTOL UK/1991 An-225 LH2/LOx Fully 7.0t
MAKS-M USSR/1989 An-225 RP-1/LH2/LOx Partly 5.5t
MAKS-OS USSR/1989 An-225 RP-1/LH2/LOx Partly 8.3t
Pegasus II USA/2011 Stratolaunch Solid+Cryo No 6.1t
Saenger II Germany/1991 Mach 4.4 turbo-ramjet LH2/LOx Fully 9.0t
Spiral 50-50 USSR/1965 Mach 6 turbo-ramjet RP-1/LOx Partly 10.0t
Teledyne-Brown USA/1986 747 LH2/LOx Fully 6.7t
Cap
tiv
e
on
Bo
tto
m Global Strike Eagle USA/2006 F-15 Solid No 0.3t
Pegasus USA/1990 L-1011 Solid No 0.5t
Yakovlev HAAL USSR/1994 Tu-160 Solid No 1.1t
© Telespazio VEGA Deutschland 20/11/2014 24
Supplementary Slides
AIR-LAUNCH MODEL INFO.
The Disruptive Potential of Subsonic Air-Launch
Wing & TPS Mass: Scales directly with materials factor (S) and the change,
with respect to the baseline, in the sum of Fuselage, Tank, Systems, and
Engine masses (Ms3 + Ms4 + Ms5 + Ms6).
Fuselage Mass: Scales directly with materials factor (S) and the change, with
respect to the baseline, in the propellant tank mass (Ms4).
Tank Mass: Scales directly with materials factor (S) and the change, with
respect to the baseline, in the propellant mass (Mf) raised to the power of 2/3.
Systems & Engine Mass: Scales directly with the change in the propellant
mass (Mf), with respect to the baseline.
RLV Design & Mission
1 Baseline mission delta-v to 400km LEO = 7820 m/s
2 Delta-v loss: 1750 m/s from sea-level; 850 m/s from 10km
3 Existing rocket engines (e.g. Merlin 1C & RL10A-4-2)
4 Oxydised/Fuel ratio: 2.28 for LOx/RP; 5.24 for LOx/LH2
5 Isp: 450s @10km for LOx/LH2; 300s @10km for LOx/RP
6 Current available structural materials (i.e. TRL 6+)
7 TPS mass: 5% Booster dry mass; 20% Orbiter dry mass
8 Wings + Empennage + body flap: 7% dry mass
ACES Characteristics [RD.10]
1 LOx collection plant (LCP) mass / volume = 4Mg / 6m3
2 Collection Ratio (CR) = 2.0 (i.e. 1kg LH2 => 2.0kg LOx)
3 LOx collection purity = 90% (i.e. 10% N2)
4 LOx collection rate = 9 kg/sec
5 Isp = 292s @10km for LOx/RP with 90% purity LOx
6 Isp = 435s @10km for LOx/LH2 with 90% purity LOx
Separation Mach number (Mn) = 12 Air-Launched +ACES Air-Launched +ACESMaterials density scaling factor (S) [%] 1.00 1.00 1.00 1.00
TSTO Booster Details TSTO Orbiter Details
Specific Impulse (Isp) [sec.] 450 435 Specific Impulse (Isp) [sec.] 450 435
Rocket equation factor (R=Exp(dV/Isp/g) 2.5968 2.6836 Rocket equation factor (R=Exp(dV/Isp/g) 2.7448 2.8421
TSTO Gross Mass (MTg=MBp+MBs+MBf) [kg] 138576 200848 Orbiter Gross Mass (M0g=MOp+MOs+MOf) [kg] 34857 48908
Booster Dry Mass (MBs=SUM(MBs1:MBs6)) [kg] 18508 25933 Orbiter Dry Mass (MOs=SUM(MOs1:MOs6)) [kg] 5379 7139
Wings Mass (MBs1) [kg] 1414 1981 Wings Mass (MOs1) [kg] 615 817
TPS Mass (MBs2) [kg] 1014 1421 TPS Mass (MOs2) [kg] 1090 1446
Fuselage Mass (MBs3) [kg] 3390 4399 Fuselage Mass (MOs3) [kg] 1251 1588
Tank Mass (MBs4) [kg] 3509 4555 Tank Mass (MOs4) [kg] 1508 1914
Systems Mass (MBs5) [kg] 2020 2987 Systems Mass (MOs5) [kg] 677 968
Engines Mass (MBs6) [kg] 7162 10590 Engines Mass (MOs6) [kg] 854 1222
FSSC-16 Defined Propellant Mass (MBf) [kg] 85211 126006 FSSC-16 Defined Propellant Mass (MOf) [kg] 22158 31700
Booster Payload (MBp=MOg, Orbiter Gross Mass) [kg] 34857 48908 Resultant TSTO Payload (MOp) [kg] 7320 10070
Booster delta-V loss (LdV) [m/s] 850 850 Orbiter delta-V loss (LdV) [m/s] --- ---
Booster delta-V (BdV) [m/s] 3363 3363 Orbiter delta-V (OdV) [m/s] 4457 4457
ACES Details TSTO System Details
LOx fraction of TSTO gross mass 65% 66% Total Mission Delta-V [m/s] 8670 8670
Total LOx propellant [kg] 90165 132436 TSTO Dry Mass (MTs=MBs+MOs) [kg] 23887 33072
LCP mass [kg] --- 4000 TSTO Gross Mass (MTg=MTs+MBf+MOf+MOp) [kg] 138576 200848
LH2 for ACES [kg] --- 66218 TSTO Gross Mass without LOx [kg] --- 68412
ACES 'kit' Mass [kg] --- 70218 TSTO Gross Mass without LOx + ACES [kg] --- 138630
© Telespazio VEGA Deutschland 20/11/2014 25
Supplementary Slides
RLV BUSINESS MODEL PARAMETERS
The Disruptive Potential of Subsonic Air-Launch
Satellite Mass
(kg)
Total No.
(2013-2022)
Annual Average
(2013-2022)
% of
Total
Below 2200 29 2.9 13%
2200 to 4200 62 6.2 27%
4200 to 54000 46 4.6 20%
54000 and
above
91 9.1 40%
Total Forecast 228 22.8 100%
Business Parameter Value range
Total R&D investment $500-1000 million
Fleet size 3 operational vehicles
Price per flight $10-20 million
Variable cost (per flight) $2-10 million
Fixed annual operating cost $40 million
Income tax rate 40%-60%
Interest rate 10% (for debt finance)
Annual flights (fleet max.) 100
First commercial launch 4 years after start
© Telespazio VEGA Deutschland 20/11/2014 26
Supplementary Slides
STEPS TOWARDS A NEW SPACE PARADIGM
The Disruptive Potential of Subsonic Air-Launch
Timeframe Future Steps Impacts
Proof of Concept
(2012-2018)
COTS payload services to ISS (~2012) MODEST: Increased microgravity
experimentation
Frequent reusable suborbital services
for tourist passengers (~2016)
SIGNIFICANT: Rapid flight vehicle
turn-around and passenger training
COTS crew rotation to ISS (~2018) MODEST: Improved human in-situ
servicing and support
Concept Maturation
(2018-2020)
Commercial space station & ELV
support (~2020)
SIGNIFICANT: Increased human in-
situ servicing and support
Air-launched RLVs for ISS cargo and
GEO satellite launch (~2020)
VERY SIGNIFICANT: Increased
satellite missions and space
infrastructure development
Air-launched RLVs for passenger
services to ISS and commercial
stations (~2023)
VERY SIGNIFICANT: Increased
human in-situ activities supporting
complex space developments
In-orbit propellant depots for crewed
exploration missions (~2025)
VERY SIGNIFICANT: Enables deep
space exploration missions and
exploitation of space resources